1. Field of the Invention
The present invention relates to a segmental hard material insert for a working tool, comprising a planar polycrystalline diamond layer having, in its layer plane, a main cutting element and a contact edge located opposite the main cutting element. The present invention also relates to a core bit provided with a hard material insert described above.
2. Description of the Prior Art
Hard material inserts of the type described above are used in working tools such as, e.g., drills, core bits, or cutting discs, for working mineral constructional components formed of, e.g., concrete, stone, or masonry.
European Publication EP 1388641 A1 discloses a hard material insert for a working tool and formed as a segment and provided with a planar polycrystalline diamond layer having, in its layer plane, a main cutting element and a contact edge located opposite the main cutting element. As a result of the rounded transitional regions of the main cutting element, the stress superelevations, which are produced by point loads and likelihood of formation of fissures in the solder layer between the working tool and the contact edge of the hard material insert, are reduced. This increases the load capacity and the service life of the hard material insert. However, there is a need to improve such a hard material insert, e.g., with regard to its efficiency in removal of the material.
Accordingly, an object of the present invention is to provide a hard material insert for a working tool and having an improved material removal efficiency in addition to a high load capacity.